The present invention relates to a liquid purification system and especially to a liquid purification system having ozone treatment units for disinfecting large volumes of fluid with ozone in a relatively small area.
Ozone has been used for the disinfection and sterilization of liquids for a great many years. Such disinfection includes the use of ozone in the treatment of sewage, swimming pool water, municipal, industrial and other water systems. The use of ozone for treating liquids was de-emphasized for many years because disinfectants, such as chlorine, gas and similar compounds was relatively inexpensive and easy to apply and continued its disinfecting action for a length of time following the initial treatment. However, the recent shortage of chlorine along with a substantial increase in its price, has resulted in new interest in the use of ozone for disinfection and sterilization. Ozone sterilization equipment typically has a system for bubbling ozone through a liquid to be treating and thereby getting sufficient contact with the ozone to sterilize the liquid. This generally requires long glass columns, or the like, in which the ozone is allowed to bubble through the narrow columns to reach a satisfactory kill of the microorganisms in the liquid being treated.
Recent studies have shown that ozone is a satisfactory means for disinfection and sterilization of sewage in that five minutes after sufficient treatment, it has been shown that better than 99.9% kill can be obtained. The effectiveness of the treatment appears to be related to the efficiency of contact between the ozone and the fluid. Recent articles dealing with ozone in the treatment of fluid are as follows: "Ozone Antidote for Water Pollution" by Hugh Thompson, and "Ozone Friend or Foe?" by E. L. Karlson, both in the May/June 1972 issue of Pollution Engineering, and in "Ozonation Today" from the June 1970 issue of Industrial Water Engineering, and in the article "Ozonation, Next Step to Water Purification" by Rene J. Bender in the August 1970 issue of Power, and in "Disinfection and Sterilization of Sewage by Ozone" by Sol Miller, Betty Burkhardt, Richard Ehrlich, and Robert John Peterson in Advances in Chemistry Series, 1957.
In addition to recent articles dealing with the use of ozone in the treatment of sewage, numerous patents have been directed toward the application of ozone in the treatment of various types of liquids. Typical prior art patents include U.S. Pat. No. 3,549,528, for Ozone Sterilization Process; U.S. Pat. No. 596,917 for an Apparatus for Sterilizing and Purifying Water; U.S. Pat. No. 1,420,046 for Method and Apparatus for Treating Liquids, and in U.S. Pat. No. 751,886 for Apparatus for Sterilizing Water. Additional U.S. Patents dealing with the treatment of liquids by ozone are U.S. Pat. Nos. 2,405,553 for a Means and Method of Ozonizing Liquids; 3,276,994 for a Sewage Treatment System; 3,772,188 for a Sewage Treatment Apparatus and Method, and 3,856,671 for a Closed-Loop Ozone Generating and Contracting System in which contactors are utilized in the treating of fluids in a ozone enriched atmosphere. U.S. Pat. No. 3,515,375 teaches a Spray Aeration System for Liquid Contact.
The present invention deals primarily with an ozone treatment system in which a contact chamber of specified design allows increased efficiency in the liquid-ozone contact cell and in which the volume of liquid that can be treated and the degree of treatment can be easily determined by the dimensions of the cell and the number of cells desired to treat a predetermined amount of liquid. The system may also be provided with additional treatment to gain a synergistic effect of the combined treatments.